A primary cell called an air battery is mounted, for example, in a hearing aid, and this primary cell must be replaced about once a week when its voltage level drops.
However, since this primary cell is very small, measuring only a few millimeters in diameter, grasping the battery, removing it from the hearing aid, and replacing it with a new one can be a surprisingly challenging task for a hearing aid user (such as an elderly person).
In view of this, the pen-type hearing aid auxiliary member shown in Patent Literature 1, for example, has been proposed.
Specifically, with a conventional pen-type hearing aid auxiliary member, an electromagnet is mounted at the tip, and the battery is picked up and taken out of the hearing aid by the attractive force of this electromagnet.
Also, with an air battery, just opening up the air hole allows a chemical reaction with oxygen to proceed, and this gradually decreases the battery capacity. In view of this, it has been proposed, as in the following Patent Literature 2, that a switching means be opened and closed with a manipulation piece provided to the outer face of the main body case, so that the air hole of the air battery is opened and closed with a cover.